Expense reporting is a huge pain in everyone’s working behind. Just this morning, my colleagues were groaning because of today’s deadline to get theirs in for the month.

So it’s at least reassuring to know that a host of companies are working on making it more pleasant. One of these, Abacus, a Y Combinator-backed startup, is reimagining expense reporting as a mobile-first tool, and the company announced today on its blog that it has raised $3.5 million in new funding.

Call me a “digital native” if you want, but Abacus reminds me of Instagram — a version of Instagram that handles my expense reporting. You take photos of your receipts and add the amount, just as you would simply add a caption to your photo. The app geo-tags your entries (you know, like tagging that photo with the dive bar where you took it). Your manager can even send you a private message regarding a particular entry (think Twitter’s direct messages).

But moving beyond the Instagram analogy, you can link your credit cards to your app, which will immediately input your purchase into your expense account. You can also get reimbursed the next day, straight into your bank account.

Managers aren’t left out, either. Abacus gives them mobile and desktop tools to quickly get in touch with employees and get clear reports of their expenses.

Abacus currently charges $5 per user, per month, but it’s free for companies that process fewer than 10 expense reports per month.

Of course, there are already a bevy of other companies that provide expense reporting tools, such as Expensify and Concur, so Abacus will have to work hard to get into the hands of employees and the hearts of managers. But it already has Pinterest, Foursquare, Coinbase, Betterment, and more than 150 additional customers, according to its blog.

Bessemer Venture Partners and General Catalyst led this round, with additional participation from Bloodstone Ventures, CrunchFund, FundersClub, Google Ventures, Homebrew, Sherpalo, Patrick and John Collison of Stripe, Josh Reeves of ZenPayroll, Jeff Epstein, former CFO of Oracle and DoubleClick, Naval Ravikant of AngelList, Andrew Kortina and Iqram Magdon-Ismail of Venmo, Adam Erlebacher of Simple, Sumon Sadhu of Quid, Nas and Paul Buchheit of Y Combinator.

Abacus was founded in 2013 by Omar Qari, Ted Power, and Joshua Halickman, and is based in New York City.